KR20110111484A - Catalysts useful for the alkylation of aromatic hydrocarbons - Google Patents

Abstract

Catalysts useful for alkylation or transalkylation of aromatic compounds are described. The catalyst comprises an acidic zeolitic catalyst comprising surface non-skeletal aluminum and skeletal aluminum with an organic dibasic acid, a weight ratio of catalyst to acid ranging from about 2: 1 to about 20: 1 and ranging from about 50 ° C to about 100 ° C. Is an acid-treated zeolitic catalyst prepared by a process comprising the step of selectively removing at least a portion of said surface non-skeleton aluminum at a temperature of. The formed catalyst may have a measured first order rate constant (k _cum ) of at least 2.0 cm ³ / sg, for alkylation of benzene with propylene to form cumene.

Description

Catalysts useful for alkylation of aromatic hydrocarbons {CATALYSTS USEFUL FOR THE ALKYLATION OF AROMATIC HYDROCARBONS}

Embodiments described herein generally relate to methods of alkylation or transalkylation of aromatic compounds with olefins, alcohols and / or alkyl halides. In another aspect, the embodiments described herein relate to methods of preparing catalysts useful for alkylation or transalkylation of aromatic compounds.

Alkylation generally relates to a kind of chemical reaction that adds alkyl groups to organic compounds. Olefins such as ethylene, propylene and butylene are well known alkylating agents frequently used in the synthesis of alkylated derivatives. Alkylation of benzene is a commercially important process used to increase the octane number of fuels and produce valuable chemical feedstocks. For example, alkylation of benzene with ethylene can be used to produce ethylbenzene, which can be subsequently converted to styrene. Similarly, alkylation of benzene with propylene can be used to produce cumene, which can be subsequently converted to phenol and acetone.

Typical alkylation of benzene is as follows:

Alkylization techniques that are still widely used in the petrochemical industry include the use of catalysts based on phosphoric acid. Newer technologies use more pollution free, corrosion free and renewable materials such as zeolitic molecular sieve catalysts. U.S. Patent Nos. 4,371,714 and 4,469,908 describe straight pass alkylation of aromatic compounds using molecular sieve catalysts in a fixed bed. However, the use of zeolitic catalysts in alkylation reactions results in two major problems: rapid deactivation of zeolitic catalysts due to coking and poisoning and high yields of polyalkylated byproducts. Other patents describing the use of zeolitic catalysts for alkylation and transalkylation may in particular include US Pat. Nos. 5,118,897, 4,083,886 and 4,891,458.

Zeolitic materials, both natural and synthetic, have been demonstrated to have catalytic properties in many types of hydrocarbon conversions, including alkylation as described above. It is often advantageous to dealuminate the materials to improve their process performance. Performance measures that are typically improved after dealumination include product selectivity, product quality, and catalyst stability.

Prior art for dealumination of zeolites includes hydrothermal treatment; Inorganic acid treatment with HCl, HNO ₃ , and H ₂ SO ₄ ; And chemical treatment with SiCl ₄ or ethylene diamine tetraacetic acid (EDTA). In many cases, at the degree of dealumination, the treatment is limited by the onset of crystallization and loss of sorption capacity. In US Pat. No. 4,419,220, dealumination through treatment of zeolite beta with HCl solution is limited to a SiO ₂ / Al ₂ O ₃ ratio of about 200 to 300 and above that a significant loss in zeolite crystallinity is observed. It is starting.

U. S. Patent No. 3,442, 795 describes a process for preparing siliceous zeolitic materials by solvolysis, for example hydrolysis, followed by chelation from crystalline aluminosilicates. In this process, the zeolite in acid form is hydrolyzed to remove aluminum from the aluminosilicate. The aluminum is then physically separated from the aluminosilicate by the use of a complexing agent or chelating agent such as ethylene diamine tetraacetic acid or carboxylic acid to form an aluminum complex, which can be easily removed from the aluminosilicate. Examples relate to the use of EDTA to remove alumina.

EP 0 259 526 B1 describes the use of dealumination in the manufacture of ECR-17. Preferred dealumination methods include a combination of steam treatment and acid leaching or chemical treatment with silicon halides. The acid used is preferably an inorganic acid such as HCl, HNO ₃ or H ₂ SO _4, but can also be a weak acid such as formic acid, acetic acid, citric acid, oxalic acid, tartaric acid and the like.

US Pat. No. 5,310,534 describes dealumination of zeolites using strong inorganic acids and organic acids such as formic acid, trichloroacetic acid, trifluoroacetic acid, hydrochloric acid, sulfuric acid and nitric acid.

In U.S. Patent 5,874,647, the catalyst is hydrothermally treated with a gas containing water and an inert component at elevated temperature and then treated with an acid such as nitric acid, oxalic acid, hydrochloric acid, methanesulfonic acid, fluorosulfonic acid and hydrofluoric acid. A process for preparing a zeolite catalyst comprising the same is described.

US Pat. No. 6,620,402 describes a process comprising dealuminating zeolites by removal of the zeolite framework or crystal structure, as obtained by removal of Al ⁺³ ions. Dealuminizing agents include inorganic acids, polyacids and chelating agents such as ammonium containing agents.

Several other patents describing the extraction of aluminum from zeolites include US Pat. Nos. 4,954,243, 5,242,676, 5,200,168, 5,304,695, 5,567,666, 5,929,295, 6,025,293, 5,723,710 and 5,321,194. Call is included.

Under conditions used in many dealumination processes of the prior art, high acidity backbone aluminum sites in the catalyst may be lost, and additionally catalyst activity may be lost. Accordingly, there is a need for a dealumination process that can selectively remove only some, non-skeletoned aluminum of alumina to improve access to the strong acid sites contained within the zeolitic structure.

Summary of the Invention

In one aspect, an aspect disclosed herein relates to a method for improving the activity of an acidic zeolitic catalyst, the method comprising an acidic zeolitic catalyst comprising surface non-skeletal aluminum and a framework aluminum with an organic dibasic acid, about 2 Selective removal of at least a portion of the surface non-skeletoned aluminum by contacting at a weight ratio of catalyst to acid in the range of from 1 to about 20: 1 and a time of up to about 2 hours at a temperature in the range of from about 50 ° C. to about 100 ° C. Forming a dealuminated zeolitic catalyst. The optionally dealuminated zeolitic catalyst may have a measured first order rate constant (k _cum ) of at least 2.0 cm ³ / sg, for alkylation of benzene with propylene to form cumene.

In another aspect, an embodiment described herein provides a) at least one C _{6 +} aromatic hydrocarbon and b) olefins, alcohols and alkyls under temperature and pressure conditions for producing at least one of the alkylate product and the transalkylate product. C) contacting at least one of the halides with an acid-treated zeolitic catalyst, wherein the acid-treated zeolitic catalyst comprises a surface non-skeletal aluminum and a backbone. An acidic zeolitic catalyst comprising aluminum is contacted with an organic dibasic acid at a weight ratio of catalyst to acid in the range from about 2: 1 to about 20: 1 and at a temperature in the range from about 50 ° C to about 100 ° C to provide the surface non-skeletoned aluminum Prepared by a method comprising the step of selectively removing at least a portion of the substrate.

In another aspect, an aspect described herein provides an acidic zeolitic catalyst comprising surface non-skeletal aluminum and skeletal aluminum comprising an organic dibasic acid, a weight ratio of catalyst to acid in the range of about 2: 1 to about 20: 1 and Contacting at a temperature in the range of from about 50 ° C. to about 100 ° C. to remove at least a portion of the surface non-skeletal aluminum, comprising the acid-treated zeolitic catalyst prepared by the method. A catalyst useful for alkylation or transalkylation.

Other aspects and advantages will be apparent from the following detailed description and the appended claims.

1 shows test results comparing the activity of an optional dealuminated zeolitic catalyst with that of an untreated zeolitic catalyst according to an embodiment described herein.

In one aspect, aspects herein relate to methods of alkylation or transalkylation of aromatic compounds with olefins, alcohols and / or alkyl halides. In another aspect, embodiments described herein relate to methods of making catalysts useful for alkylation or transalkylation of aromatic compounds.

Catalysts useful in the embodiments described herein include acidic zeolitic catalysts, such as silica-alumina and aluminosilicate, which have been selectively treated to remove some of the aluminum from the catalyst by treatment with organic dibasic acids. Aluminum-containing catalysts useful herein are characterized by having crystalline skeletal structures and precisely defined pore structures composed of assemblies of silicon and aluminum atoms, each surrounded by a tetrahedron of shared oxygen atoms. Exchangeable cations may be present in the pores. In addition to framework aluminum, the aluminum containing catalysts useful in the embodiments described herein can have non-skeletal and extra-framework aluminum that is not integrated with the crystalline framework structure. Treatment of an acidic zeolitic catalyst with an organic dibasic acid in accordance with the methods described herein can selectively remove non-skeletal aluminum to increase the overall acidity of the catalyst. In some embodiments, acid treatment may be performed under conditions such that only non-skeleton aluminum is removed from the catalyst such that no aluminum is necessarily extracted from the backbone of the catalyst.

The catalyst may also contain from about 0% to about 10% by weight of one or more optional elements, including titanium, zirconium, hafnium, tantalum, and niobium; In other embodiments, from about 0.01% to about 3% by weight. These optional elements may be incorporated into the catalytic material prior to selective dealumination or introduced into the material after selective dealumination.

Optionally dealuminated catalysts according to embodiments described herein may be contacted with an acidic zeolitic catalyst comprising surface non-skeletoned aluminum and skeletal aluminum with an organic dibasic acid to selectively remove at least a portion of the surface non-skeletoned aluminum. It can be manufactured by. The amount of organic dibasic acid required for selective dealumination may depend on the specific composition of the given acidic zeolitic catalyst and its physical properties. In general, in some embodiments, the amount of organic dibasic acid used during the treatment step may be an amount such that the weight ratio of catalyst to acid ranges from about 1.5: 1 to about 20: 1. In other embodiments, the ratio of catalyst to acid ranges from about 2: 1 to about 20: 1; In another embodiment in a range from about 2: 1 to about 15: 1; In another embodiment in a range from about 2.5: 1 to about 12: 1; In other embodiments, from about 3.5: 1 to about 10: 1; And still in other embodiments, from about 6: 1 to about 8: 1.

The acidic zeolitic catalyst was mixed with the organic dibasic acid solution in some embodiments for 5 minutes to 2 hours; In other embodiments, the contact can be made for a time range of 30 minutes to 90 minutes. Selective dealumination of the acidic zeolitic catalyst can be carried out in a single step or in multiple steps. Selective dealumination is carried out at optional mild conditions, for example at temperatures in the range of about 50 ° C. to about 100 ° C. in some embodiments; In other embodiments, it may be carried out at a temperature ranging from about 65 ° C to about 90 ° C. During contact with the organic dibasic acid, the slurry can be stirred continuously or intermittently.

After contact with the organic dibasic acid for selective dealumination, excess solution in the treatment vessel must be drained, and optionally the dealuminated catalyst can be washed with a sufficient amount of clean deionized water. The catalyst can then be dried, for example, at a temperature in the range of about 80 ° C to about 150 ° C.

Acidic zeolitic catalysts that can be optionally dealuminated according to embodiments described herein can include natural zeolites and synthetic zeolites. Acidic crystalline zeolite structures useful in the embodiments described herein can be obtained by lamination of three-dimensional network of bonded AlO ₄ and SiO ₄ tetrahedra by sharing oxygen atoms. Thus, the framework structure obtained contains pores, channels and cages or interconnected voids. Since trivalent aluminum ions at the lattice position replace tetravalent silicon ions, the net structure has a net negative charge, which must be supplemented by a counterion (cationic). Such cations are mobile and may occupy several exchange sites, for example depending on their radius, charge or degree of hydration. They can also be replaced by exchange with other cations to varying degrees. Because of the need to maintain electrical neutrality, there is a direct 1: 1 relationship between the aluminum content in the backbone and the number of positive charges provided by the exchange cations. If the exchange cation is a proton, the zeolite is acidic. Therefore, the acidity of the zeolite is measured by the amount of protons exchanged with other cations relative to the amount of aluminum.

Zeolitic catalysts that may be used in some embodiments described herein may include zeolites with large pore sizes, zeolites with medium pore sizes, and zeolites with small pore sizes. Such zeolites are described in "Atlas of Zeolite Structure Types," eds. W. H. Meier and D. H. Olson, Butterworth-Heineman, Third Edition, 1992. Zeolites with large pore sizes generally have pore sizes greater than about 7 mm 3 and include, for example, LTL, VFI, MAZ, MEI, FAU, EMT, OFF, BEA and MOR structured zeolites (zeolite nomenclature of the IUPAC committee). Examples of zeolites with large pore sizes include, for example, mazite, mordenite, opreite, zeolite L, VPI-5, zeolite Y, zeolite X, omega, beta, ZSM-3, ZSM-4, ZSM-18, And ZSM-20. Zeolites with medium pore sizes generally have a pore size of about 5 kPa to about 7 kPa, for example MFI, MFS, MEL, MTW, EUO, MTT, HEU, FER and TON structured zeolites (zeolite nomenclature of the IUPAC committee) It includes. Examples of zeolites with medium pore sizes include ZSM-5, ZSM-12, ZSM-22, ZSM-23, ZSM-34, ZSM-35, ZSM-38, ZSM-48, ZSM-50, Silicalite and Silyl Callite 2 is included. Small pore sizes of zeolites generally have a pore size of about 3 kPa to about 5.0 kPa and include, for example, zeolites of CHA, ERI, KFI, LEV, and LTA structure types (zeolite nomenclature of the IUPAC committee). Examples of zeolites with small pore sizes include ZK-4, ZK-14, ZK-21, ZK-22, ZK-5, ZK-20, Zeolite A, Erionite, Chabazite, Zeolite T, Gemlineite, and Clie Noftyolite is included.

Clay or amorphous catalysts comprising silica-alumina and fluorinated silica-alumina may also be used. Further discussion of alkylation catalysts can be found in US Pat. Nos. 5,196,574, 6,315,964 and 6,617,481. Several types of zeolitic catalysts can be used for alkylation as well as other types of catalyst purification processes. In FCC processes, for example, one or more of Y, beta, and ZSM-5 types can be used. FCC zeolitic catalysts typically contain three parts, typically about 30-50% by weight of the zeolite, active matrix and binder in the catalyst particles. In one embodiment, the particle size of the FCC catalyst may be between 50 and 60 μm. In another embodiment, the zeolitic catalyst is initially in ammonium form, which can be converted to H ⁺ form by heating to a temperature above 300 ° C. before being used as alkylation catalyst. It is to be noted that the catalyst is not overheated prior to alkylation because excess temperature can dealuminize the zeolite and shrink the ring structure to reduce the activity of the alkylation reaction. In addition to zeolitic catalysts, inorganic catalysts such as sulfated zirconia or tungstenized zirconia can also be used for alkylation. Other useful zeolitic catalysts may include ZSM-22, ZSM-23, MCM-22 and MCM-49.

In some embodiments, suitable catalysts for alkylation and transalkylation may include metal stabilization catalysts. For example, such catalysts may include zeolite components, metal components and inorganic oxide components. Zeolites may be pentasil zeolites and include MFI, MEL, MTW, MTT and FER (zeolite nomenclature of the IUPAC committee), MWW, beta zeolite or mordenite structures. Metal components are typically precious and base metals, and the remainder of the catalyst may consist of inorganic oxide binders such as alumina. Other catalysts having a zeolitic structure that can be used in the embodiments described herein are described, for example, in US Pat. No. 7,253,331, which is incorporated herein by reference.

Before or after the optional dealumination, the acidic zeolitic catalyst may be a porous matrix material, for example alumina, silica, titania, zirconia, silica-alumina, silica-magnesia, silica-zirconia, silica-toria, silica-berilia , Silica-titania, as well as ternary compositions such as silica-alumina-tria, silica-alumina-zirconia, silica-alumina-magnesia and silica-magnesia-zirconia. The matrix may be in the form of a cogel. The relative proportions of the zeolite component and the inorganic oxide gel matrix can be very broad, with zeolite content ranging from 1 to 99% by weight, more generally 5 to 80% by weight of the composite.

Organic dibasic acids useful for the selective dealumination process according to embodiments described herein can include various dicarboxylic acids. Suitable acids may include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, tartaric acid, maleic acid, phthalic acid or mixtures thereof. Other useful carboxylic acids include 1,2-cyclopentane dicarboxylic acid, fumaric acid, itaconic acid, phthalic acid, terephthalic acid, phenylmalonic acid, hydroxyphthalic acid, dihydroxyfumaric acid, tricavalrylic acid and benzene-1,3,5-tricarboxylic acid. May be included. Dicarboxylic acids can be used as solutions, for example aqueous dicarboxylic acid solutions. Tricarboxylic acids such as citric acid and higher polycarboxylic acids can also be used. More than one acid treatment step may be used to achieve the desired selective dealumination in the processes described herein.

As a result of dealumination at conditions suitable for selectively dealumination of only non-skeletoned aluminum, the catalysts according to the embodiments described herein can be used in the alkylation and transalkylation reactions, for example benzene with propylene to produce cumene. May exhibit exceptionally high activity in alkylation reactions. For example, an optional dealumination catalyst according to an embodiment described herein may have a first order rate constant (k _cum ) when measured under controlled test conditions as described in the following test procedure. Has an activity of at least 2 cm ³ / sg. In another embodiment, the first order rate constant (k _cum ) is at least 2.25 cm ³ / sg; In other embodiments, at least 2.5 cm ³ / sg; In other embodiments at least ³ cm ³ / sg; In other embodiments, at least 3.25 cm ³ / sg; In other embodiments, at least 3.5 cm ³ / sg; And in other embodiments at least 4 cm ³ / sg.

For example, in some embodiments, the beta zeolite is selectively dealuminated according to embodiments described herein such that the first order rate constant (k _cum ) is at least 2 cm ³ / sg; In other embodiments, at least 2.1 cm ³ / sg; In other embodiments, at least 2.2 cm ³ / sg; In other embodiments, at least 2.5 cm ³ / sg; And in other embodiments an optional dealuminated catalyst that is at least ³ cm ³ / sg.

As another example, in some embodiments, high performance beta zeolites are optionally dealuminated according to embodiments described herein such that the primary rate constant (k _cum ) is at least 2.5 cm ³ / sg; In other embodiments at least ³ cm ³ / sg; In other embodiments, at least 3.5 cm ³ / sg; In other embodiments, at least 3.75 cm ³ / sg; And in other embodiments, an optional dealuminated catalyst that is at least 4 cm ³ / sg.

Accordingly, selective dealumination of the catalyst according to embodiments described herein may comprise forming an aqueous solution of organic dibasic acid; Contacting the acidic zeolitic catalyst by mixing with the aqueous solution; Separating the acid-contacted zeolitic catalyst from the aqueous solution; Washing the acid-contacted catalyst to remove all excess organic dibasic acid; And drying the washed catalyst at a temperature in the range of about 80 ° C to about 150 ° C.

In addition, because of the processing conditions and acid: catalyst capacity used herein, the additional processing steps typically used to dealuminate the zeolite catalyst can be omitted. For example, many prior art dealumination processes involve hydrothermal or other pretreatment of zeolites prior to acid treatment. Selective dealumination according to the embodiments described herein can be performed while forming a catalyst with exceptionally high activity without the pretreatment step. Thus, the catalyst preparation process according to the embodiments described herein can be carried out in the absence of hydrothermal treatment steps or other conventional pretreatment steps used for dealumination of zeolites.

The optional dealumination catalyst described above can be used to alkylate or transalkylate aromatic compounds with various alkylating agents, including olefins, alcohols and alkyl halides. Such catalysts may additionally be used for the alkylation of isoparaffins with olefins and / or alcohols, as well as for fluid catalytic cracking (FCC) or hydrocracking processes.

In some embodiments of the alkylation and transalkylation methods described herein, the olefin is reacted with an aromatic hydrocarbon such as benzene to form an alkylate or transalkylate product. In some embodiments, the olefins for alkylation or trans alkylation of aromatic hydrocarbons are those containing 2 to 6 carbon atoms. In another embodiment, the olefins for alkylation or transalkylation of aromatic hydrocarbons are those containing 2 to 4 carbon atoms, for example ethylene, propylene, butene-1, trans-butene-2 and cis-butene-2 or theirs Mixture.

The olefin feed stream used in the various embodiments described herein may also contain certain impurities such as the corresponding C ₂ to C ₄ paraffins. Typically, impurities, including dienes, acetylene, water, sulfur compounds or nitrogen compounds, which may be present in the olefin feedstock stream, are removed prior to alkylation and transalkylation reactions to prevent rapid catalyst deactivation. In some cases, however, it may be desirable to add small amounts of water or nitrogen compounds in a controlled manner to optimize catalyst properties.

In other embodiments, olefins useful in the embodiments described herein may include up to 20 carbon atoms. For example, olefins having more than six carbon atoms can be used.

Alcohols useful in the embodiments described herein can include C ₁ to C ₆ primary and secondary alcohols. The term "alcohol" includes lower alkyl alcohols capable of forming an azeotrope of the hydrocarbon feedstock with saturated and unsaturated hydrocarbons, especially C ₃ to C ₇ hydrocarbons. Examples of alcohols useful in the embodiments described herein include methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol and t-butanol. In some embodiments, the methanol may be used in combination with one or more of the C _{2 +} alcohol.

Alkyl halides useful in the embodiments described herein can include mono- or poly-halogenated C ₂ to C ₆ hydrocarbons such as alkyl chlorides and alkyl bromides. For example, alkyl halides useful in the embodiments described herein can include methyl, ethyl, propyl and butyl halides, higher homologs thereof and isomers thereof.

In an aspect of the alkylation process described herein, a hydrocarbon feedstock containing an aromatic substance, such as benzene, reacts with olefins in the presence of an alkylation catalyst to replace alkyl benzene, which may be useful as a special chemical feedstock or as a high octane gasoline component. Form. In particular, one aspect described herein relates to the reaction of a benzene with C ₂ to C ₄ olefins to form a monoalkylate product in the presence of an alkylation catalyst. Detailed process steps and process conditions may vary depending on the catalyst system used. In another embodiment, a heterogeneous slurry catalyst is used to promote the alkylation reaction. By way of illustration, but not by way of limitation, some representative alkylation reactions of olefins with benzene are:

1) Ethylene + Benzene → Ethylbenzene

2) Propylene + Benzene → Isopropylbenzene (cumene)

3) n-butylene + benzene → butylbenzene

4) Isobutylene + Benzene → Isobutylbenzene

In addition to monoalkylate products, other undesirable products in the form of heavy hydrocarbons typically include, but are not limited to, polyalkylates, heavy flux oils (including non-transalkylated components) and polymerized feed olefins. To calculate.

Transalkylation reactions can be used to prepare monoalkylate products by reacting benzene with polyalkylates. If transalkylation is desired, the transalkylating agent is a polyalkylate aromatic hydrocarbon containing at least two alkyl groups, each of which may have from 2 to about 4 carbon atoms. For example, suitable polyalkylate aromatic hydrocarbons include di-, tri- and tetra-alkyl aromatic hydrocarbons such as diethylbenzene, triethylbenzene, diethylmethylbenzene (diethyltoluene), diisopropylbenzene, tri Isopropylbenzene, diisopropyltoluene, dibutylbenzene and the like. In one particular embodiment, the polyalkylate aromatic hydrocarbon is diisopropylbenzene, which reacts with benzene to form cumene (isopropylbenzene).

Reaction products obtainable from the transalkylation process of benzene include ethylbenzene from the reaction of benzene with ethylene or polyethylbenzenes; Cumene from the reaction of benzene with propylene or polyisopropylbenzene; Ethyltoluene from the reaction of toluene with ethylene or polyethyltoluene; Cymen from the reaction of toluene with propylene or polyisopropyltoluene; And secondary-butylbenzene from the reaction of benzene with n-butylene or polybutylbenzene. For illustrative purposes, but not limited to this process, some representative transalkylation reactions of polyalkylates with benzene are as follows:

1) Diethylbenzene + benzene → 2 ethylbenzene

2) diisopropylbenzene + benzene → 2 isopropylbenzene (cumene)

3) dibutylbenzene + benzene → 2 butylbenzene

Various types of reactors can be used in the alkylation process as well as in the transalkylation process. The choice of reactor type for use in alkylation or transalkylation reactions may depend on a number of factors including the desired mode of operation, throughput volume and reaction control parameters such as residence time and product yield.

Large scale industrial processes typically use a continuous flow reactor as a fixed bed or mobile bed reactor. Mobile phase reactors typically operate with cocurrent or countercurrent catalysts, olefins and hydrocarbons. Such reactors may contain a single catalyst phase or multiple phases and may be equipped for interstage addition and intermediate cooling of olefins. Interstage olefin addition and closer isothermal operation improve product quality and catalyst life. Mobile phase reactors enable regeneration and the continuous removal of spent catalyst for replacement with fresh or regenerated catalyst.

In mobile bed reactors, alkylation is completed in a relatively short reaction zone after the introduction of olefins. 10-30% of the reacting aromatic molecules may be alkylated more than once. Transalkylation is a slower reaction that occurs in both the transalkylation and alkylation reaction zones. If the transalkylation proceeds to equilibrium, the selectivity for the monoalkylated product generally occurs greater than 90% by weight. Thus, transalkylation increases the yield of monoalkylated products by reacting polyalkylated products with benzene.

In the selective monoalkylation of aromatics with olefins, as catalyzed by a selectively dealuminated catalyst in accordance with embodiments described herein, the olefins, alcohols and alkyl halides may be from 2 to at least 20 carbon sources. And may be branched or linear at the end or in the middle. Thus, the particular nature of the alkylating agent is not particularly important.

Benzene is by far the most important representative of the alkylable aromatic compounds that can be used in the embodiments described herein. More generally, the aromatic compound may be selected from the group consisting of benzene, naphthalene, anthracene, phenanthrene and substituted derivatives thereof. The most important class of substituents found in the aromatic nucleus of an alkylable aromatic compound is an alkyl moiety containing from 1 to about 20 carbon atoms. Another important substituent is a hydroxyl moiety and an alkoxy moiety, the alkyl groups of which also contain up to 20 carbon atoms. If the substituent is an alkyl or alkoxy group, the phenyl moiety may also be substituted in the paraffin chain. In the practice of the present invention, although unsubstituted and monosubstituted benzenes, naphthalenes, anthracenes and phenanthrenes are most often used, polysubstituted aromatics can also be used. In addition to those cited above, examples of suitable alkylable aromatic compounds include biphenyl, toluene, xylene, ethylbenzene, propylbenzene, butylbenzene, pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene and the like; Phenol, cresol, anisole, ethoxy-, propoxy-, butoxy-, pentoxy-, hexoxybenzene and the like.

Pressures in alkylation conditions may range from about 200 to about 1,000 psig (1379 to 6985 kPa), but are generally in the range of about 300 to 600 psig (2069 to 4137 kPa). Representative alkylation temperatures range from 200 to 250 ° C. for alkylation of benzene with ethylene and from 90 to 200 ° C. for alkylation of benzene with propylene. Suitable temperature ranges for alkylation of alkylable aromatic compounds of the invention using olefins in the C ₂ to C ₂₀ range are about 60 to about 400 ° C., the most common temperature range being about 90 to 250 ° C.

The ratio of alkylable aromatic compound to alkylating agent used in the process can depend on the desired selective monoalkylation as well as the relative cost of the aromatic and olefinic components in the reaction mixture. In the case of alkylation of benzene with propylene, the ratio of benzene to olefin is from a low ratio of about 1 to a high ratio of about 10, with a ratio of 2.5 to 8 being preferred. When alkylating benzene with ethylene, a ratio of about 1: 1 to 8: 1 benzene to olefins is preferred. For olefins in the C ₆ -C ₂₀ detergent range, a benzene to olefin ratio of 5: 1 to 30: 1 or less is generally sufficient to ensure the desired monoalkylation selectivity, and from about 8: 1 to about 20: 1 The range is even more preferred.

As mentioned above, catalysts according to embodiments described herein can also be used to catalyze alkylation as well as transalkylation. "Transalkylation" means a process wherein an alkyl group of one aromatic nucleus is transferred between molecules to a second aromatic nucleus. Transalkylation of particular interest herein is a reaction in which one or more alkyl groups of a polyalkylated aromatic compound is transferred to a nonalkylated aromatic compound, wherein diisopropylbenzene and benzene react to give two molecules of cumene. . Thus, transalkylation is often used to add the selectivity of the desired optional monoalkylation by reacting polyalkylates formed unaltered during alkylation with non-alkylated aromatics to form additional monoalkylation products. For the purposes of this section, polyalkylated aromatic compounds are compounds formed in the alkylation reaction of alkylable aromatic compounds with olefins as described above, and non-alkylated aromatic compounds are benzene, naphthalene, anthracene and phenanthrene. The reaction conditions of the transalkylation are similar to those of the alkylation, the temperature ranges from 100 to about 250 ° C., the pressure ranges from 100 to about 750 psig, and the ratio of nonalkylated aromatics to polyalkylated aromatics is from about 1 to about 10 Range. For example, examples of the polyalkylated aromatic material capable of reacting with benzene as the non-alkylated aromatic material include diethylbenzene, diisopropylbenzene, dibutylbenzene, triethylbenzene, triisopropylbenzene and the like.

Example

Test procedure for applying cumene

The catalytic activity of the zeolite beta catalysts in the alkylation of benzene with propylene to form cumene was evaluated. The test reactor was a recycle fine powder stationary bed reactor (7/8 inch ID SS tube) and the test conditions were a pressure of 350 psig, a temperature of 17O <0> C and a recycle rate of 200 g / min. Test feeds containing 0.35 to 0.45% by weight of propylene were dissolved in benzene with a feed rate of 6.0 g / min. The charge of the catalyst with a particle size of 12 to 20 mesh derived from 1.6 mm extrudates containing 80 wt% zeolite and 20 wt% binder was 0.7 g, after the catalyst was dried at 350 ° C. for 2 hours. Was charged to the reactor. Tests were run for 7-8 hours using samples taken every 30 minutes for gas chromatography (GC) analysis. The first reaction rate (k) was calculated to determine the activity of the catalyst for the alkylation of benzene with propylene to form cumene.

Catalyst preparation

Comparative Example 1 [Commercial Beta]

Zeolite beta catalysts used in this Example and Examples 1-7 were obtained from Zeolith International Co., Valley Forge, Pennsylvania, USA. The catalyst as obtained was a 1.6 mm extrudate containing 80 wt% zeolite and was resized to 12-20 mesh particles. Alkylation of benzene with propylene to produce cumene was tested for catalytic activity using a portion of the catalyst particles using the procedure described above, followed by the acid treatment described in Examples 1-7 for the remainder of the catalyst particles. The evaluation was carried out and the results are shown in Table 1 and shown in FIG. 1.

Example 1

An aqueous solution formed by dissolving 0.50 g of oxalic acid dihydrate in 200 mL of deionized (DI) water was heated to 70 ° C. 5.0 g of catalyst particles from Comparative Example 1 were then added to the solution and the resulting mixture was kept at 70 ° C. for 1 hour with stirring. After cooling the mixture to 25 ° C., the solid material was collected by vacuum filtration. The solid thus obtained was added to 500 mL of deionized (DI) water and the resulting mixture was heated to 70 ° C. and kept at this temperature for 1 hour with stirring. Finally, the solid was collected by vacuum filtration and dried in an oven at 120 ° C. overnight.

Example 2

An aqueous solution formed by dissolving 1.0 g of oxalic acid dihydrate in 200 mL of deionized (DI) water was heated to 70 ° C. 5.0 g of catalyst particles from Comparative Example 1 were then added to the solution and the resulting mixture was kept at 70 ° C. for 1 hour with stirring. After cooling the mixture to 25 ° C., the solid material was collected by vacuum filtration. The solid thus obtained was added to 500 mL of deionized (DI) water and the resulting mixture was heated to 70 ° C. and kept at this temperature for 1 hour with stirring. Finally, the solid was collected by vacuum filtration and dried in an oven at 120 ° C. overnight.

Example 3

An aqueous solution formed by dissolving 2.0 g of oxalic acid dihydrate in 200 mL of deionized (DI) water was heated to 70 ° C. 5.0 g of catalyst particles from Comparative Example 1 were then added to the solution and the resulting mixture was kept at 70 ° C. for 1 hour with stirring. After cooling the mixture to 25 ° C., the solid material was collected by vacuum filtration. The solid thus obtained was added to 500 mL of deionized (DI) water and the resulting mixture was heated to 70 ° C. and kept at this temperature for 1 hour with stirring. Finally, the solid was collected by vacuum filtration and dried in an oven at 120 ° C. overnight.

Example 4

An aqueous solution formed by dissolving 3.0 g of oxalic acid dihydrate in 200 mL of deionized (DI) water was heated to 70 ° C. 5.0 g of catalyst particles from Comparative Example 1 were then added to the solution and the resulting mixture was kept at 70 ° C. for 1 hour with stirring. After cooling the mixture to 25 ° C., the solid material was collected by vacuum filtration. The solid thus obtained was added to 500 mL of deionized (DI) water and the resulting mixture was heated to 70 ° C. and kept at this temperature for 1 hour with stirring. Finally, the solid was collected by vacuum filtration and dried in an oven at 120 ° C. overnight.

Example 5

An aqueous solution formed by dissolving 10.0 g of oxalic acid dihydrate in 200 mL of deionized (DI) water was heated to 70 ° C. 5.0 g of catalyst particles from Comparative Example 1 were then added to the solution and the resulting mixture was kept at 70 ° C. for 1 hour with stirring. After cooling the mixture to 25 ° C., the solid material was collected by vacuum filtration. The solid thus obtained was added to 500 mL of deionized (DI) water and the resulting mixture was heated to 70 ° C. and kept at this temperature for 1 hour with stirring. Finally, the solid was collected by vacuum filtration and dried in an oven at 120 ° C. overnight.

Example 6

An aqueous solution formed by dissolving 25.0 g of oxalic acid dihydrate in 200 mL of deionized (DI) water was heated to 70 ° C. 5.0 g of catalyst particles from Comparative Example 1 were then added to the solution and the resulting mixture was kept at 70 ° C. for 1 hour with stirring. After cooling the mixture to 25 ° C., the solid material was collected by vacuum filtration. The solid thus obtained was added to 500 mL of deionized (DI) water and the resulting mixture was heated to 70 ° C. and kept at this temperature for 1 hour with stirring. Finally, the solid was collected by vacuum filtration and dried in an oven at 120 ° C. overnight.

Example 7

An aqueous solution formed by dissolving 0.87 g of malonic acid in 200 mL of deionized (DI) water was heated to 70 ° C. 5.0 g of catalyst particles from Comparative Example 1 were then added to the solution and the resulting mixture was kept at 70 ° C. for 1 hour with stirring. After cooling the mixture to 25 ° C., the solid material was collected by vacuum filtration. The solid thus obtained was added to 500 mL of deionized (DI) water and the resulting mixture was heated to 70 ° C. and kept at this temperature for 1 hour with stirring. Finally, the solid was collected by vacuum filtration and dried in an oven at 120 ° C. overnight.

Comparative Example 2 (High Performance Beta)

The high performance beta (“HP” Beta) used in this Example and Examples 8-19 was in the form of 1.6 mm extrudates containing 80 wt% zeolite and 20 wt% binder according to the method described in US Pat. No. 6,809,055. Prepared. For the reactor evaluation and the acid treatment described in Examples 8-19, the extrudate was sized to 12-20 mesh. The test results of these samples along with the acid treated samples are summarized in Table 2.

Example 8

An aqueous solution formed by dissolving 0.50 g of oxalic acid dihydrate in 200 mL of deionized (DI) water was heated to 70 ° C. 5.0 g of catalyst particles from Comparative Example 2 were then added to the solution and the resulting mixture was kept at 70 ° C. for 1 hour with stirring. After cooling the mixture to 25 ° C., the solid material was collected by vacuum filtration. The solid thus obtained was added to 500 mL of deionized (DI) water and the resulting mixture was heated to 70 ° C. and kept at this temperature for 1 hour with stirring. Finally, the solid was collected by vacuum filtration and dried in an oven at 120 ° C. overnight.

Example 9

An aqueous solution formed by dissolving 1.0 g of oxalic acid dihydrate in 200 mL of deionized (DI) water was heated to 70 ° C. 5.0 g of catalyst particles from Comparative Example 2 were then added to the solution and the resulting mixture was kept at 70 ° C. for 1 hour with stirring. After cooling the mixture to 25 ° C., the solid material was collected by vacuum filtration. The solid thus obtained was added to 500 mL of deionized (DI) water and the resulting mixture was heated to 70 ° C. and kept at this temperature for 1 hour with stirring. Finally, the solid was collected by vacuum filtration and dried in an oven at 120 ° C. overnight.

Example 10

An aqueous solution formed by dissolving 2.0 g of oxalic acid dihydrate in 200 mL of deionized (DI) water was heated to 70 ° C. 5.0 g of catalyst particles from Comparative Example 2 were then added to the solution and the resulting mixture was kept at 70 ° C. for 1 hour with stirring. After cooling the mixture to 25 ° C., the solid material was collected by vacuum filtration. The solid thus obtained was added to 500 mL of deionized (DI) water and the resulting mixture was heated to 70 ° C. and kept at this temperature for 1 hour with stirring. Finally, the solid was collected by vacuum filtration and dried in an oven at 120 ° C. overnight.

Example 11

An aqueous solution formed by dissolving 25.0 g of oxalic acid dihydrate in 200 mL of deionized (DI) water was heated to 70 ° C. 5.0 g of catalyst particles from Comparative Example 2 were then added to the solution and the resulting mixture was kept at 70 ° C. for 1 hour with stirring. After cooling the mixture to 25 ° C., the solid material was collected by vacuum filtration. The solid thus obtained was added to 500 mL of deionized (DI) water and the resulting mixture was heated to 70 ° C. and kept at this temperature for 1 hour with stirring. Finally, the solid was collected by vacuum filtration and dried in an oven at 120 ° C. overnight.

Example 12

An aqueous solution formed by dissolving 2.0 g of oxalic acid dihydrate in 200 mL of deionized (DI) water was heated to 85 ° C. 5.0 g of catalyst particles from Comparative Example 2 were then added to the solution and the resulting mixture was maintained at 85 ° C. for 1 hour with stirring. After cooling the mixture to 25 ° C., the solid material was collected by vacuum filtration. The solid thus obtained was added to 500 mL of deionized (DI) water and the resulting mixture was heated to 85 ° C. and kept at this temperature for 1 hour with stirring. Finally, the solid was collected by vacuum filtration and dried in an oven at 120 ° C. overnight.

Example 13

An aqueous solution was formed by dissolving 2.0 g of oxalic acid dihydrate in 200 mL of deionized (DI) water. Then 5.0 g of catalyst particles from Comparative Example 2 were added to the solution and the resulting mixture was stirred at 22 ° C. for 1 hour. The solid material was collected by vacuum filtration, washed with 500 mL of deionized (DI) water and dried in an oven at 120 ° C. overnight.

Example 14

An aqueous solution was formed by dissolving 2.0 g of oxalic acid dihydrate in 200 mL of deionized (DI) water. 5.0 g of catalyst particles from Comparative Example 2 were then added to the solution and the resulting mixture was stirred at 22 ° C. for 6 hours. The solid material was collected by vacuum filtration, washed with 500 mL of deionized (DI) water and dried in an oven at 120 ° C. overnight.

Example 15

An aqueous solution (200 mL) containing 3.5% by weight of HNO ₃ was heated to 70 ° C. Then 5.0 g of catalyst particles from Comparative Example 2 were added to the solution and the resulting mixture was stirred at 70 ° C. for 1 hour. After cooling the mixture to 25 ° C., the solid material was collected by vacuum filtration. The solid thus obtained was added to 500 mL of deionized (DI) water and the resulting mixture was heated to 70 ° C. and kept at this temperature for 1 hour with stirring. Finally, the solid was collected by vacuum filtration and dried in an oven at 120 ° C. overnight.

Example 16

An aqueous solution (200 mL) containing 0.7 wt% HNO ₃ was heated to 70 ° C. Then 5.0 g of catalyst particles from Comparative Example 2 were added to the solution and the resulting mixture was stirred at 70 ° C. for 1 hour. After cooling the mixture to 25 ° C., the solid material was collected by vacuum filtration. The solid thus obtained was added to 500 mL of deionized (DI) water and the resulting mixture was heated to 70 ° C. and kept at this temperature for 1 hour with stirring. Finally, the solid was collected by vacuum filtration and dried in an oven at 120 ° C. overnight.

Example 17

Catalyst particles (5.0 g) from Comparative Example 2 were added to an aqueous solution (200 mL) containing 0.7 wt.% HNO ₃ and the mixture was stirred at 22 ° C. for 1 hour. The catalyst particles were then collected by vacuum filtration, washed with 500 mL of deionized (DI) water and dried in an oven at 120 ° C. overnight.

Example 18

An aqueous solution formed by dissolving 1.35 g of acetic acid in 200 mL of deionized (DI) water was heated to 70 ° C. 5.0 g of catalyst particles from Comparative Example 2 were then added to the solution and the resulting mixture was kept at 70 ° C. for 1 hour with stirring. After cooling the mixture to 25 ° C., the solid material was collected by vacuum filtration. The solid thus obtained was added to 500 mL of deionized (DI) water and the resulting mixture was heated to 70 ° C. and kept at this temperature for 1 hour with stirring. Finally, the solid was collected by vacuum filtration and dried in an oven at 120 ° C. overnight.

Example 19

An aqueous solution formed by dissolving 0.87 g of malonic acid in 200 mL of deionized (DI) water was heated to 70 ° C. 5.0 g of catalyst particles from Comparative Example 2 were then added to the solution and the resulting mixture was kept at 70 ° C. for 1 hour with stirring. After cooling the mixture to 25 ° C., the solid material was collected by vacuum filtration. The solid thus obtained was added to 500 mL of deionized (DI) water and the resulting mixture was heated to 70 ° C. and kept at this temperature for 1 hour with stirring. Finally, the solid was collected by vacuum filtration and dried in an oven at 120 ° C. overnight.

Test procedures and results for alkylation of linear alkylalkylbenzenes are shown below: Catalysts of Commercial Beta (Same Sample as Used in Comparative Example 1) and Acid Treated Beta (Same Sample as Used in Example 2) Activity was evaluated. All experiments were conducted in one liter autoclave with a stirrer. For alkylation of benzene with 1-dodecene, the reaction was carried out at 140 ° C. using 1.25 g of catalyst, 112 g of benzene and 12 g of 1-dodecene. In the case of alkylation of benzene with pacholate, the reaction was carried out at 140 ° C. using 0.625 g of catalyst, 60 g of benzene, and 60 g of parcholate containing 50 g of paraffin (C ₁₀ -C ₁₄ ) and 6 g of olefin (C ₁₀ -C ₁₄ ). Was carried out. The reaction mixture was analyzed by GC at reaction times of 2.5, 4.0 and 6.0 hours (hr) and the conversion rates are summarized in Table 3 below.

As mentioned above, embodiments described herein provide zeolitic catalysts suitable for use in alkylation and transalkylation processes. Zeolitic catalysts are dealuminated at specific acid to catalyst ratios and reaction conditions to selectively remove at least some of the non-skeletoned aluminum. In some embodiments, the dealumination process according to embodiments described herein may advantageously remove only surface non-skeletal aluminum while leaving the skeleton aluminum intact. Selective dealumination according to embodiments described herein can enhance the strong acid sites contained in the catalyst. Thus, optionally dealuminated catalysts in accordance with embodiments described herein may have active acid sites that provide easier access to the desired aromatic alkylation and transalkylation reactions.

While the present invention has been described in a limited number of embodiments, those skilled in the art will clearly appreciate that other embodiments may be practiced without departing from the scope of the present invention while having the benefit of the present invention. Accordingly, the scope of the invention should be limited only by the appended claims.

Claims (25)

As a method of improving the activity of an acidic zeolitic catalyst,
The method
Acidic zeolitic catalysts, including surface non-framework aluminum and skeletal aluminum, may be prepared by combining organic dibasic acids with a weight ratio of catalyst to acid ranging from about 2: 1 to about 20: 1 and from about 50 ° C to about 100 ° C. Contacting at a temperature in the range of about 2 hours or less to selectively remove at least a portion of the surface non-skeletoned aluminum to form a selectively dealuminated zeolitic catalyst,
Wherein said selectively dealuminated zeolitic catalyst has a measured first order rate constant (k _cum ) of at least 2.0 cm ³ / sg relative to alkylation of benzene with propylene to form cumene. The method of claim 1,
Forming an aqueous solution of the organic dibasic acid;
Contacting the acidic zeolitic catalyst by mixing with the aqueous solution;
Separating the acid-contacted zeolitic catalyst from the aqueous solution;
Washing the acid-contacted catalyst to remove all excess organic dibasic acid; And
Drying the washed catalyst at a temperature in a range from about 80 ° C. to about 150 ° C.
Further comprising. The method of claim 1, wherein contacting the zeolitic catalyst with an organic dibasic acid selectively removes only surface non-skeleton aluminum. The method of claim 1, wherein the weight ratio of catalyst to acid ranges from about 6: 1 to about 8: 1. The method of claim 4, wherein the selectively dealuminated zeolitic catalyst has a measured first order rate constant (k _cum ) of at least ³ cm ³ / sg, for alkylation of benzene with propylene to form cumene. Way. The method of claim 1, wherein the organic dibasic acid comprises at least one of oxalic acid, malonic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, tartaric acid, ethylene diamine tetraacetic acid, and mixtures thereof. The method of claim 1, wherein the zeolitic catalyst comprises at least one of silica-alumina and aluminosilicate. The method of claim 1, wherein the contacting is conducted at a temperature in a range from about 65 ° C. to about 90 ° C. for 0.5 to 1.5 hours. The method of claim 1, wherein the zeolitic catalyst comprises at least one of zeolite beta, ZSM-5, ZSM-22, ZSM-23, MCM-22 and MCM-49. The method of claim 1, wherein the acidic zeolitic catalyst comprises a high performance beta zeolite, and wherein the selectively dealuminated zeolitic catalyst is at least 4 cm ³ / sg for alkylation of benzene with propylene to form cumene With the first order rate constant k _cum measured. As an alkylation or transalkylation method of an aromatic hydrocarbon,
The method
Under conditions of temperature and pressure for the production of at least one of the alkylate product and the trans alkylate product, a) at least one C _{6 +} aromatic hydrocarbon and b) an olefin, at least one of the alcohol and alkyl halides c) acid-treated zeolite Contacting the active catalyst,
The acid-treated zeolitic catalyst comprises an acidic zeolitic catalyst comprising surface non-skeletal aluminum and skeletal aluminum with an organic dibasic acid, a weight ratio of catalyst to acid ranging from about 2: 1 to about 20: 1 and about 50 Selectively removing at least a portion of the surface non-skeleton aluminum by contacting at a temperature in the range of from about 100 ° C. to about 100 ° C. The method of claim 11, wherein contacting the zeolitic catalyst with an organic dibasic acid selectively removes only surface non-skeleton aluminum. The method of claim 11, wherein the catalyst has a measured first order rate constant (k _cum ) of at least 2 cm ³ / sg, for alkylation of benzene with propylene to form cumene. The method of claim 11, wherein the weight ratio of catalyst to acid ranges from about 6: 1 to about 8: 1. The method of claim 14, wherein the catalyst has a measured first order rate constant (k _cum ) of at least ³ cm ³ / sg, for alkylation of benzene with propylene to form cumene. The method of claim 11, wherein the organic dibasic acid comprises at least one of oxalic acid, malonic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, tartaric acid, ethylene diamine tetraacetic acid, and mixtures thereof. The method of claim 11, wherein the zeolitic catalyst comprises at least one of silica-alumina and aluminosilicate. The method of claim 11, wherein the contacting is carried out at a temperature in a range from about 65 ° C. to about 90 ° C. for 0.5 to 1.5 hours. The method of claim 11, wherein the zeolitic catalyst comprises at least one of zeolite beta, ZSM-5, ZSM-22, ZSM-23, MCM-22 and MCM-49. The method of claim 11, wherein the acid-treated zeolitic catalyst is prepared by
Forming an aqueous solution of the organic dibasic acid;
Contacting the acidic zeolitic catalyst by mixing with the aqueous solution;
Separating the acid-contacted zeolitic catalyst from the aqueous solution:
Washing the acid-contacted catalyst to remove all excess organic dibasic acid; And
Drying the washed catalyst at a temperature in a range from about 80 ° C. to about 150 ° C. The method of claim 11, wherein the acidic zeolitic catalyst comprises a high performance beta zeolite, and wherein the selectively dealuminated zeolitic catalyst is at least 4 cm ³ / sg for alkylation of benzene with propylene to form cumene. With the first order rate constant k _cum measured. As a catalyst useful for alkylation or transalkylation of aromatic compounds,
Contacting an acidic zeolitic catalyst comprising surface non-skeletal aluminum and skeletal aluminum with an organic dibasic acid at a weight ratio of catalyst to acid ranging from about 2: 1 to about 20: 1 and at a temperature ranging from about 50 ° C to about 100 ° C. And an acid-treated zeolitic catalyst prepared by a process comprising selectively removing at least a portion of said surface non-skeleton aluminum. The method of claim 22, wherein the method of preparing the catalyst is
Forming an aqueous solution of the organic dibasic acid;
Contacting the acidic zeolitic catalyst by mixing with the aqueous solution;
Separating the acid-contacted zeolitic catalyst from the aqueous solution;
Washing the acid-contacted catalyst to remove all excess organic dibasic acid; And
And drying the washed catalyst at a temperature in the range of about 80 ° C to about 150 ° C. The catalyst of claim 22 wherein the catalyst has a measured first order rate constant (k _cum ) of at least 2 cm ³ / sg for alkylation of benzene with propylene to form cumene. 23. The method of claim 22, wherein the acidic zeolitic catalyst comprises a high performance beta zeolite and wherein the selectively dealuminated zeolitic catalyst is at least 4 cm ³ / sg for alkylation of benzene with propylene to form cumene Catalyst with the first order rate constant k _cum measured.

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